Always show own topics in the listing even when you're unsubscribed from the group it's in
Basically the title, the primary case where this would be useful is when you post a topic in say ~news (which you're subscribed to) and then someone moves it to ~misc (which you're not subscribed to). The topic now "disappeared" but if you go to your profile it's still there.
Presumably, if you post something then there's a reasonable expectation that you're also interested in the potential comments, so having it always show up in your listing (regardless of your group subscriptions) could be helpful. And for the case that you're not interested, the ignore button is always available.